This application claims priority to U.S. provisional patent application No. 62/616,676 filed Jan. 12, 2018, which is hereby incorporated by reference herein in its entirety.
BACKGROUNDThis relates generally to electronic devices, and, more particularly, to electronic devices with displays.
Electronic devices often include displays. For example, an electronic device may have an organic light-emitting diode display based on organic-light-emitting diode pixels or a liquid crystal display based on liquid crystal pixels. In some cases, it may be desirable for a display to have a curved display surface. However, it may be difficult to curve conventional organic light-emitting diode displays and liquid crystal displays to have the desired curved display surface.
It would therefore be desirable to be able to provide improved displays for electronic devices.
SUMMARYAn electronic device may have a display such as an organic light-emitting diode display or a liquid crystal display. To allow the display to have a curved output surface, the display may include a plurality of fibers.
Each fiber may guide light from one or more display pixels on the display panel to a display output surface. The fibers may be bent, allowing light from the display pixels to be displayed on a three-dimensional display output surface of any desired shape. The fibers may be formed from a high refractive index core surrounded by a cladding. The fibers may be attached to a flexible substrate that is then attached to an electronic device component such as the interior surface of the display cover layer.
The fibers may also be formed by activating a photoactive material using one or more light sources. One light source may be used to form a plurality of linear fibers in the photoactive material, or two or more light sources may be used to form non-linear fibers in the photoactive material. The light source for activating the photoactive material may be a laser that emits visible or ultraviolet light.
The fibers may cover any desired portion of the underlying display panel. For example, the fibers may cover the entire display panel, the periphery of the display panel, or the corners of the display panel. The display panel may also have one or more bends to help form the desired display output surface.
Organic light-emitting diode displays and liquid crystal displays may include a linear polarizer layer. To reduce the thickness of the display and the distance between the display plane and the display output surface, polarizing fibers may be used to both guide light from the display panel and serve as the linear polarizer. In some embodiments, the polarizing fibers may extend into openings of the display cover layer such that the ends of the fibers form an outermost surface of the electronic device. This allows the display cover layer to be an opaque material such as a metal or a ceramic.
BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is a schematic diagram of an illustrative electronic device having a display in accordance with an embodiment.
FIG. 2 is a schematic diagram of an illustrative display in accordance with an embodiment.
FIG. 3 is a cross-sectional side view of an illustrative liquid crystal display in accordance with an embodiment.
FIG. 4 is a cross-sectional side view of an illustrative organic light-emitting diode display in accordance with an embodiment.
FIG. 5 shows cross-sectional side views of steps for forming a fiber relay in accordance with an embodiment.
FIG. 6 is a cross-sectional side view of an illustrative electronic device with a fiber relay between a display panel and a flexible substrate in accordance with an embodiment.
FIG. 7 is a flowchart of illustrative method steps for forming a fiber relay between a display panel and a display cover layer in accordance with an embodiment.
FIG. 8 shows cross-sectional side views of steps for forming a fiber using a photoactive material and a single light source in accordance with an embodiment.
FIG. 9 shows cross-sectional side views of steps for forming a fiber using a photoactive material and two or more light sources in accordance with an embodiment.
FIG. 10 is a flowchart of illustrative method steps for using photoactive material to form a fiber relay between a display panel and a display cover layer in accordance with an embodiment.
FIGS. 11A-11C are top views of illustrative displays showing how fibers may be used to guide light from different portions of the displays in accordance with an embodiment.
FIG. 12 is a top view of an illustrative display panel that is bent in accordance with an embodiment.
FIG. 13 is a cross-sectional side view of an illustrative electronic device with a bent display panel and a fiber relay in accordance with an embodiment.
FIG. 14 is a top view of an illustrative display panel with multiple bends in accordance with an embodiment.
FIG. 15 is a perspective view of the illustrative display panel ofFIG. 14 after the display panel has been bent in accordance with an embodiment.
FIG. 16 is a cross-sectional side view of an illustrative electronic device with fibers between a linear polarizer and a display cover layer in accordance with an embodiment.
FIG. 17 is a cross-sectional side view of an illustrative electronic device with polarizing fibers that replace the function of a linear polarizer in accordance with an embodiment.
FIG. 18 is a cross-sectional side view of an illustrative electronic device with polarizing fibers that form an outermost surface of the electronic device in accordance with an embodiment.
FIG. 19 is a cross-sectional side view of an illustrative electronic device with fibers that protrude into openings in the display cover layer to form an outermost surface of the electronic device in accordance with an embodiment.
DETAILED DESCRIPTIONAn illustrative electronic device of the type that may be provided with a display is shown inFIG. 1.Electronic device10 may be a computing device such as a laptop computer, a computer monitor containing an embedded computer, a tablet computer, a cellular telephone, a media player, or other handheld or portable electronic device, a smaller device such as a wrist-watch device, a pendant device, a headphone or earpiece device, a device embedded in eyeglasses or other equipment worn on a user's head, or other wearable or miniature device, a display, a computer display that contains an embedded computer, a computer display that does not contain an embedded computer, a gaming device, a navigation device, an embedded system such as a system in which electronic equipment with a display is mounted in a kiosk or automobile, or other electronic equipment.Electronic device10 may have the shape of a pair of eyeglasses (e.g., supporting frames), may form a housing having a helmet shape, or may have other configurations to help in mounting and securing the components of one or more displays on the head or near the eye of a user.
As shown in the example ofFIG. 1,device10 may have a housing such ashousing12.Housing12 may be formed from plastic, metal (e.g., aluminum), fiber composites such as carbon fiber, glass, ceramic, other materials, and combinations of these materials.Housing12 or parts ofhousing12 may be formed using a unibody construction in which housing structures are formed from an integrated piece of material. Multipart housing constructions may also be used in which housing12 or parts ofhousing12 are formed from frame structures, housing walls, and other components that are attached to each other using fasteners, adhesive, and other attachment mechanisms. Glass structures, transparent polymer structures, image transport layer structures, and/or other transparent structures that coverdisplay14 and other portions ofdevice10 may provide structural support fordevice10 and may sometimes be referred to as housing structures. For example, a glass or polymer layer that covers and protects a pixel array indisplay14 may serve as a display cover layer while also serving as a housing structure fordevice10.
As shown inFIG. 1,electronic device10 may includecontrol circuitry18 for supporting the operation ofdevice10. The control circuitry may include storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory configured to form a solid state drive), volatile memory (e.g., static or dynamic random-access memory), etc. Processing circuitry incontrol circuitry18 may be used to control the operation ofdevice10. The processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio chips, application specific integrated circuits, etc.
Input-output circuitry indevice10 such as input-output devices16 may be used to allow data to be supplied todevice10 and to allow data to be provided fromdevice10 to external devices. Input-output devices16 may include buttons, joysticks, scrolling wheels, touch pads, key pads, keyboards, microphones, speakers, tone generators, vibrators, cameras, sensors, light-emitting diodes and other status indicators, data ports, etc. A user can control the operation ofdevice10 by supplying commands through input-output devices16 and may receive status information and other output fromdevice10 using the output resources of input-output devices16.
Input-output devices16 may include one or more displays such asdisplay14.Display14 may be a touch screen display that includes a touch sensor for gathering touch input from a user ordisplay14 may be insensitive to touch. A touch sensor fordisplay14 may be based on an array of capacitive touch sensor electrodes, acoustic touch sensor structures, resistive touch components, force-based touch sensor structures, a light-based touch sensor, or other suitable touch sensor arrangements. A touch sensor fordisplay14 may be formed from electrodes formed on a common display substrate with the pixels ofdisplay14 or may be formed from a separate touch sensor panel that overlaps the pixels ofdisplay14. If desired,display14 may be insensitive to touch (i.e., the touch sensor may be omitted).
Control circuitry18 may be used to run software ondevice10 such as operating system code and applications. During operation ofdevice10, the software running oncontrol circuitry18 may display images ondisplay14.
FIG. 2 is a diagram of an illustrative display. As shown inFIG. 2,display14 may include layers such assubstrate layer26. Substrate layers such aslayer26 may be formed from rectangular planar layers of material or layers of material with other shapes (e.g., circular shapes or other shapes with one or more curved and/or straight edges). The substrate layers ofdisplay14 may include glass layers, polymer layers, composite films that include polymer and inorganic materials, metallic foils, etc.
Display14 may have an array ofpixels22 for displaying images for a user such aspixel array28.Pixels22 inarray28 may be arranged in rows and columns. The edges ofarray28 may be straight or curved (i.e., each row ofpixels22 and/or each column ofpixels22 inarray28 may have the same length or may have a different length). There may be any suitable number of rows and columns in array28 (e.g., ten or more, one hundred or more, or one thousand or more, etc.).Display14 may includepixels22 of different colors. As an example,display14 may include red pixels, green pixels, and blue pixels. If desired, a backlight unit may provide backlight illumination fordisplay14.
Display driver circuitry20 may be used to control the operation ofpixels28.Display driver circuitry20 may be formed from integrated circuits, thin-film transistor circuits, and/or other suitable circuitry. Illustrativedisplay driver circuitry20 ofFIG. 2 includesdisplay driver circuitry20A and additional display driver circuitry such asgate driver circuitry20B.Gate driver circuitry20B may be formed along one or more edges ofdisplay14. For example,gate driver circuitry20B may be arranged along the left and right sides ofdisplay14 as shown inFIG. 2.
As shown inFIG. 2,display driver circuitry20A (e.g., one or more display driver integrated circuits, thin-film transistor circuitry, etc.) may contain communications circuitry for communicating with system control circuitry oversignal path24.Path24 may be formed from traces on a flexible printed circuit or other cable. The control circuitry may be located on one or more printed circuits inelectronic device10. During operation, control circuitry (e.g.,control circuitry18 ofFIG. 1) may supply circuitry such as a display driver integrated circuit incircuitry20 with image data for images to be displayed ondisplay14.Display driver circuitry20A ofFIG. 2 is located at the top ofdisplay14. This is merely illustrative.Display driver circuitry20A may be located at both the top and bottom ofdisplay14 or in other portions ofdevice10.
To display the images onpixels22,display driver circuitry20A may supply corresponding image data to data lines D while issuing control signals to supporting display driver circuitry such asgate driver circuitry20B oversignal paths30. With the illustrative arrangement ofFIG. 2, data lines D run vertically throughdisplay14 and are associated with respective columns ofpixels22.
Gate driver circuitry20B (sometimes referred to as gate line driver circuitry or horizontal control signal circuitry) may be implemented using one or more integrated circuits and/or may be implemented using thin-film transistor circuitry onsubstrate26. Horizontal control lines G (sometimes referred to as gate lines, scan lines, emission control lines, etc.) run horizontally throughdisplay14. Each gate line G may be associated with a respective row ofpixels22. If desired, there may be multiple horizontal control lines such as gate lines G associated with each row of pixels. Individually controlled and/or global signal paths indisplay14 may also be used to distribute other signals (e.g., power supply signals, etc.).
Gate driver circuitry20B may assert control signals on the gate lines G indisplay14. For example,gate driver circuitry20B may receive clock signals and other control signals fromcircuitry20A onpaths30 and may, in response to the received signals, assert a gate line signal on gate lines G in sequence, starting with the gate line signal G in the first row ofpixels22 inarray28. As each gate line is asserted, data from data lines D may be loaded into a corresponding row of pixels. In this way, control circuitry such asdisplay driver circuitry20A and20B may providepixels22 with signals thatdirect pixels22 to display a desired image ondisplay14. Eachpixel22 may have a light-emitting diode and circuitry (e.g., thin-film circuitry on substrate26) that responds to the control and data signals fromdisplay driver circuitry20.
Gate driver circuitry20B may include blocks of gate driver circuitry such as gate driver row blocks. Each gate driver row block may include circuitry such output buffers and other output driver circuitry, register circuits (e.g., registers that can be chained together to form a shift register), and signal lines, power lines, and other interconnects. Each gate driver row block may supply one or more gate signals to one or more respective gate lines in a corresponding row of the pixels of the array of pixels in the active area ofdisplay14.
Display14 may be a liquid crystal display or an organic light-emitting diode display, as examples.FIG. 3 is a cross-sectional side view of an illustrative liquid crystal display fordevice10. As shown inFIG. 3,display14 may include backlight structures such asbacklight unit42 for producingbacklight44. During operation,backlight44 travels outwards (vertically upwards in dimension Z in the orientation ofFIG. 3) and passes through pixels in display layers46. This illuminates any images that are being produced by the pixels for viewing by a user. For example,backlight44 may illuminate images on display layers46 that are being viewed byviewer48 indirection50. Display layers46 may sometimes collectively be referred to as a display panel.
Display layers46 may be mounted in chassis structures such as a plastic chassis structure and/or a metal chassis structure to form a display module for mounting inhousing12 or display layers46 may be mounted directly in housing12 (e.g., by stacking display layers46 into a recessed portion in housing12). Display layers46 may form a liquid crystal display or may be used in forming displays of other types.
Display layers46 may include a liquid crystal layer such aliquid crystal layer52.Liquid crystal layer52 may be sandwiched between display layers such as display layers58 and56.Layers56 and58 may be interposed between lower (inner)polarizer layer60 and upper (outer)polarizer layer54.
Layers58 and56 may be formed from transparent substrate layers such as clear layers of glass or plastic.Layers58 and56 may be layers such as a thin-film transistor layer and/or a color filter layer. Conductive traces, color filter elements, transistors, and other circuits and structures may be formed on the substrates oflayers58 and56 (e.g., to form a thin-film transistor layer and/or a color filter layer). Touch sensor electrodes may also be incorporated into layers such aslayers58 and56 and/or touch sensor electrodes may be formed on other substrates.
With one illustrative configuration,layer58 may be a thin-film transistor layer that includes an array of pixel circuits based on thin-film transistors and associated electrodes (pixel electrodes) for applying electric fields toliquid crystal layer52 and thereby displaying images ondisplay14.Layer56 may be a color filter layer that includes an array of color filter elements for providingdisplay14 with the ability to display color images. If desired,layer58 may be a color filter layer andlayer56 may be a thin-film transistor layer. Configurations in which color filter elements are combined with thin-film transistor structures on a common substrate layer in the upper or lower portion ofdisplay14 may also be used.
During operation ofdisplay14 indevice10, control circuitry (e.g., one or more integrated circuits on a printed circuit) may be used to generate information to be displayed on display14 (e.g., display data). The information to be displayed may be conveyed to a display driver integrated circuit such ascircuit62A or62B using a signal path such as a signal path formed from conductive metal traces in a rigid or flexible printed circuit such as printed circuit64 (as an example).
Backlight structures42 may include a light guide layer such aslight guide layer78.Light guide layer78 may be formed from a transparent material such as clear glass or plastic (e.g., molded plastic that forms a light guide plate, a thin flexible plastic film, etc.). During operation ofbacklight structures42, a light source such as light source72 may generate light74. Light source72 may be, for example, an array of light-emitting diodes.
Light74 from light source72 may be coupled intoedge surface76 oflight guide plate78 and may be distributed in dimensions X and Y throughoutlight guide layer78 due to the principal of total internal reflection.Light guide layer78 may include light-scattering features such as pits or bumps or other light-scattering structures. The light-scattering features may be located on an upper surface and/or on an opposing lower surface oflight guide layer78. Light source72 may be located at the left oflight guide layer78 as shown inFIG. 3 or may be located along the right edge oflayer78 and/or other edges oflayer78.
Light74 that scatters upwards in direction Z fromlight guide layer78 may serve asbacklight44 fordisplay14.Light74 that scatters downwards may be reflected back in the upwards direction byreflector80.Reflector80 may be formed from a reflective material such as a layer of plastic covered with a dielectric mirror thin-film coating.
To enhance backlight performance forbacklight structures42,backlight structures42 may includeoptical films70.Optical films70 may include diffuser layers for helping to homogenizebacklight44 and thereby reduce hotspots, compensation films for enhancing off-axis viewing, and light collimating films such as brightness enhancement films and turning films.Optical films70 may overlap the other structures inbacklight unit42 such aslight guide layer78 andreflector80. For example, iflight guide layer78 has a rectangular footprint in the X-Y plane ofFIG. 3,optical films70 andreflector80 may have a matching rectangular footprint. If desired, films such as compensation films may be incorporated into other layers of display14 (e.g., polarizer layers).
Display14 may include one or more additional layers such aslayer82 on top ofpolarizer54. For example, layers such aslayer82 may include a wave plate or other optical film to adjust the polarization of thelight exiting display14.
FIG. 4 is a cross-sectional side view of an illustrative organic light-emitting diode display for use indevice10. As shown inFIG. 4,display14 may include a substrate layer such assubstrate layer90.Substrate90 may be formed from a polymer or other suitable materials. Thin-film transistor circuitry92 may be formed onsubstrate90. Thinfilm transistor circuitry92 may include inorganic layers such as inorganic buffer layers, barrier layers (e.g., barrier layers to block moisture and impurities), gate insulator, passivation, interlayer dielectric, and other inorganic dielectric layers. Thin-film transistor circuitry92 may also include organic dielectric layers such as a polymer planarization layer. Metal layers and semiconductor layers may be included within thin-film transistor circuitry92 to form transistors and light-emitting diodes. For example, semiconductors such as silicon, semiconducting-oxide semiconductors, or other semiconductor materials may be used in forming semiconductor channel regions for thin-film transistors. Metal may be used in forming transistor gate terminals, transistor source-drain terminals, capacitor electrodes, and metal interconnects.
Light-emittingdiodes94 may be formed from the patterned layers of material in thin-film transistor circuitry92 and may serve as pixels fordisplay14. In each light-emitting diode, organic emissive material and other light-emitting diode layers may be interposed between a respective anode and cathode. During operation, light-emittingdiodes94 may emit light96 for forming images for viewing byviewer48. Layers such aslayers98 and100 may be formed on top of thin-film transistor circuitry92.Layer100 may be a circular polarizer for suppressing ambient light reflections from metal structures and other reflective structures in thin-film transistor circuitry92.Circular polarizer100 may include a linear polarizer and a quarter-wave plate.Optional layer98 may be a wave plate or other optical film for adjusting the polarization of emittedlight96. Wave plates indevice10 may be formed from single-layer structures or multi-layer structures to provide broadband transmission spectrums and wide viewing angles. The organic light-emitting diode display structures shown inFIG. 4 may sometimes be referred to as a display panel.
In some cases, it may be desirable fordisplay14 to have a curved display surface. To form a curved display surface,display14 may optionally be bent. However,display14 may only tolerate bending in one direction (e.g., along one bending axis). Therefore, to allow a display surface to be curved in two directions (or to avoid any bending of display14), the display may include a fiber relay (sometimes referred to as a group of fibers). The fiber relay may include a plurality of fibers that guide light from the display panel to the desired display output surface. The fibers may be flexible, enabling the display output surface to have any desired three-dimensional shape. For example, the display output surface may be curved in two directions, otherwise known as having compound curvature. When bent along only one direction, the display output surface may be flattened into a plane without distortion (sometimes referred to as developable surfaces). When bent along two directions, the display output surface has compound curvature (e.g., a surface that can only be flattened into a plane with distortion, sometimes referred to as a surface with Gaussian curvature).
FIG. 5 shows a cross-sectional side view of the formation of an illustrative fiber relay (sometimes referred to as a fiber bundle) for use in an electronic device display. As shown inFIG. 5, at step302 a plurality of fibers may be encased in a host matrix material.Fiber relay142 may include a plurality offibers144 that are surrounded byhost matrix material146. Eachfiber144 may include acore148 that is surrounded by cladding150. The cores may be formed from a clear material such as glass, polymer, etc. The index of refraction of the core may be greater than the index of refraction of the cladding to promote total internal reflection.Host matrix material146 may be any desired material and may maintain the structural integrity offiber relay142. If desired, cladding150 may be omitted from eachfiber144.
Atstep304,fiber relay142 may be attached between two substrates. As shown, a first end of eachfiber144 infiber relay142 may be attached tosubstrate152 whereas a second opposing end of eachfiber144 infiber relay142 may be attached tosubstrate154.Substrates152 and154 may be any desired layer or material.Substrate152 may be a flexible substrate that can later be bent to form a desired display surface.Substrate152 may sometimes be referred to as elastomeric and may be formed from any desired material (e.g., rubber, silicone, etc.). In one illustrative example,substrate154 may be a display layer (e.g., a layer of display14). For example,substrate154 may be an upper polarizer (e.g., upper polarizer54), a thin-film transistor layer (e.g., thin-film transistor layer58), a color filter layer (e.g., color filter layer56) or a wave plate or other optical film (e.g., additional layer82) of a liquid crystal display (e.g., the liquid crystal display inFIG. 3). As yet other examples,substrate154 may be a layer of thin-film transistor circuitry (e.g., thin-film transistor circuitry92), a circular polarizer (e.g., circular polarizer100) or a wave plate or other optical film (e.g., additional layer98) of an organic light-emitting diode display (e.g., the organic light-emitting diode display inFIG. 4).
Atstep306host matrix material146 may be removed fromfiber relay142. When thehost matrix material146 is removed, the remainingfibers144 are free to bend into any desired shape. Therefore, iffiber relay142 is attached to a display structure, the fiber relay allows light fromdisplay14 to be mapped to the surface of any desired three-dimensional shape (e.g., an output surface having compound curvature).
FIG. 6 is a cross-sectional side view of an illustrative electronic device with a fiber relay of the type shown inFIG. 5. As shown,fiber relay142 may includefibers144, with each fiber having a core surrounded by a cladding. One end of each fiber may be attached to display panel160 (e.g.,display panel160 may serve assubstrate154 fromFIG. 5). The other end of each fiber may be attached toflexible substrate152. Theflexible substrate152 may then in turn be attached to an interior surface ofdisplay cover layer162.Display cover layer162 may be a layer of clear glass, plastic, or other dielectric that covers the light-emitting surface of the underlying display panel. In another suitable arrangement,display cover layer162 may be the outermost layer of display14 (e.g.,layer162 may be a color filter layer, thin-film transistor layer, or other display layer). Buttons may pass through openings incover layer162. The cover layer may also have other openings such as an opening for a speaker port, openings for a sensor, or openings for any other desired electronic component.
As shown inFIG. 6,fiber relay142 may be used to direct light from a planar edge portion of the display panel to a curved output surface. Becausefibers144 andsubstrate152 are flexible, the light may be directed to an output surface of any desired shape. The flexible substrate may be attached to the interior surface ofdisplay cover layer162 with adhesive (e.g., transparent adhesive).
The example inFIG. 6 offiber relay142 being used to direct light from the display panel to a display cover layer is merely illustrative. In general,fiber relay142 may direct light from the display panel to any desired display output surface. For example, the fiber relay may be attached to the electronic device housing (e.g.,housing12 inFIG. 1) or another device component (instead of the display cover layer).
If desired, afiller material164 may be formed in betweenfibers144 offiber relay142 afterflexible substrate152 is attached to displaycover layer162.Filler material164 may conform to the shape of the fibers to fill any voids between the fibers. This may help maintain the structural integrity of the fibers and keep the fibers in a desired position.Filler material164 may be any desired material.
Eachfiber144 may be aligned with one pixel indisplay14. Alternatively, each pixel may be overlapped by multiple fibers. In yet another embodiment, each fiber may overlap multiple pixels. In general, each pixel may be overlapped by any desired number of pixels (e.g., exactly one, more than one, less than one, etc.). Different pixels may also be overlapped by different numbers of fibers.
Eachfiber144 inFIG. 6 has a uniform cross-section across the length of the fiber. This example is merely illustrative. If desired, the cross-section of the fiber may change along the length of the fiber. For example, the cross-section of the fiber may progressively increase in surface area moving from the display panel to the display cover layer. In this way, the light from the display panel can be magnified onto a larger area on the display cover layer.
FIG. 7 is a flowchart of illustrative method steps for forming a fiber relay that maps output from a display panel to an arbitrary three-dimensional shape. As shown, atstep402 fibers that are encased in a host matrix material may be attached between a display panel (e.g., any layer in a display) and a flexible substrate. Once attached to the flexible substrate and display panel, the host matrix material may be removed atstep404. Once the host matrix material is removed, the fibers may be free to flex into any desired position based on the position of the flexible substrate. Atstep406, the flexible substrate may be attached to a display cover layer (or other desired electronic device component such as a housing). The flexible substrate may be attached to a curved interior surface of a transparent display cover layer (as shown inFIG. 6), for example. Optionally, an additional filler material may be formed around the fibers of the fiber relay once the fiber relay is attached between the display panel and the display cover layer.
The example inFIGS. 5-7 of the fiber relay being formed from a plurality of fibers (each with a high refractive index core surrounded by cladding) initially encased in a host matrix material is merely illustrative. In another embodiment, fibers may be formed by activating a photoactive material using controlled exposure to light.
FIG. 8 is a cross-sectional side view of an illustrative electronic device during formation of a fiber using a photoactive material. As shown inFIG. 8, at step502 aphotoactive material170 is formed betweendisplay panel160 anddisplay cover layer162.Photoactive material170 may undergo a chemical or physical change in response to exposure to a particular type of light. There are many types of photoactive materials that may be used. In one example,photoactive material170 may be a photopolymer. Polymerization of the material may be initiated by exposure to light. For example,photoactive material170 may initially be formed entirely of monomers. The portions ofphotoactive material170 that are then exposed to light will polymerize to become polymers. In another embodiment,photoactive material170 may be a chalcogenide glass. When exposed to light, the exposed portions of the chalcogenide glass may have a higher index of refraction than portions that are not exposed to the light, forming light guiding channels.
FIG. 8 shows an embodiment where a single light source is used to activatephotoactive material170. As shown,light source172 emits a beam oflight174 throughphotoactive material170.Light source172 may emit any desired type of light that activatesphotoactive material170. For example,light source172 may emit visible light, ultraviolet light, or infrared light.Light source172 may be a laser or another desired type of light source.
Atstep502 whenlight source172 emitsbeam174 throughphotoactive material170,region176 ofphotoactive material170 is activated by the light. As shown inFIG. 8 atstep504, this results in the formation of achannel178.Channel178 may be a portion ofphotoactive material170 that has been activated to form a fiber for a fiber relay.Channel178 may have a high refractive index that allows the channel to guide light fromdisplay panel160 to display cover layer162 (or another desired electronic device structure). Multiple channels may be formed usingphotoactive material170 to form a fiber relay. Each channel may form a respective fiber for the fiber relay. Each fiber may be aligned with exactly one pixel indisplay14, multiple pixels indisplay14, or a portion of a pixel indisplay14.
Using a single light source to activatephotoactive material170 may result in each fiber having a linear structure (e.g., each fiber extends along a single axis). Multiple light sources may instead by used to produce fibers with any desired three-dimensional structure. In this technique, multiple light sources may emit beams throughphotoactive material170. However, only portions ofphotoactive material170 that are exposed to both light sources will be activated. This enables the activated portion to be precisely controlled in three-dimensions through the photoactive material.
FIG. 9 shows an embodiment where multiple light sources are used to activatephotoactive material170. As shown,light source172A emits a beam of light174A throughphotoactive material170 andlight source172B emits a beam of light174B throughphotoactive material170.Light sources172A and172B may emit any desired type of light that activates photoactive material170 (e.g., visible light, ultraviolet light, infrared light etc.).Light sources172A and172B may be lasers or other desired types of light sources.
Atstep602 whenlight source172A emitsbeam174A throughphotoactive material170 andlight source172B emitsbeam174B throughphotoactive material170,region176 ofphotoactive material170 that is exposed to bothbeams174A and174B may be activated. As shown inFIG. 9 atstep604, this intersection point between the beams may be moved in any direction in three-dimensions to form achannel178 with any desired shape.Channel178 is the portion ofphotoactive material170 that has been activated to form a fiber for the fiber relay. Due to being activated by the light exposure,channel178 may have a high refractive index that allows the channel to guide light fromdisplay panel160 to display cover layer162 (or another desired electronic device structure). Multiple channels may be formed in this way usingphotoactive material170 to form a fiber relay. Each channel may form a fiber for the fiber relay. Each fiber may be aligned with exactly one pixel indisplay14, multiple pixels indisplay14, or a portion of a pixel indisplay14.
FIG. 10 is a flowchart of illustrative method steps for forming a fiber relay using a photoactive material. As shown inFIG. 10, atstep702 the photoactive material may be positioned between the two substrates of interest (or positioned above one substrate, with the additional substrate to be added after activation). For example, when the fiber relay is used to relay light from a display panel to a curved display output surface, the photoactive material may be positioned between the display panel and the display cover layer. Next, atstep704, one or more light sources may be used to activate the photoactive material and form one or more fibers for the fiber relay. Portions of the photoactive material that are exposed to light from the one or more light sources may be activated and form a channel that guides light from the display panel to the display cover layer. One light source may be used to form a plurality of linear fibers or multiple light sources may be used to form fibers with non-linear shapes. Once all of the fibers have been formed in the photoactive material, the remaining photoactive material may optionally be exposed to a capping agent that reduces the reactivity of the photoactive material.
If desired, the portions of the photoactive material that were not activated instep704 may remain between the display panel and the display cover layer. These remaining portions may act as a host matrix that help maintain the shape of the fibers. Alternatively, the portions of the photoactive material that were not activated instep704 may optionally be removed atstep706. If the portions of the photoactive material that were not activated instep704 are removed atstep706, an additional filler material may optionally be added atstep708. The additional filler material may conform to the shape of the fibers and fill any voids between the fibers. This may help maintain the structural integrity of the fibers and keep the fibers in a desired position. Any desired material may be used as the additional filler material instep708.
As previously discussed, fiber relays may use a plurality of fibers to guide light from a display panel to a display output surface. The fiber relay may be used to cover (and guide light from) any desired portion of the display panel.FIGS. 11A-11C are top views showing various arrangements with at least a portion of the display panel covered by fibers.
FIG. 11A shows anillustrative display14 where the entire display panel is covered byfiber relay142. In other words, every pixel may emit light into one or more fibers that then guide the emitted light to a display output surface. The display output surface may have any desired shape. In some embodiments, a central portion of the display output surface may be planar while a peripheral portion of the display output surface may be curved. The corner portions of the display output surface may have compound curvature, for example. In the central portion of the fiber relay, fibers may guide light straight up from the central portion of the display panel to the display output surface (without any curvature). Fibers that overlap the peripheral portions of the display, however, may be bent in order to guide light to the curved edges of the display output surface.
In another embodiment, shown inFIG. 11B, only a portion of the display panel may be covered by fibers. In the example ofFIG. 11B, the peripheral portion of the display panel is covered byfiber relay142 whereas the central portion of the display panel is not covered byfiber relay142. In this type of arrangement, a central portion of the display output surface may be planar (because light is being emitted from the central portion of the display without modification by the fibers). An edge portion of the display output surface, however, may use thefiber relay142 to have any desired three-dimensional shape. For example, the fiber relay may be used to create a curved edge for the display output surface around the entire periphery of the display. The display output surface may have compound curvature in each of the four corners of the display and may have curvature along a single axis along the edges that extend between the four corners. This example of the entire periphery of the display output surface having a curved edge is merely illustrative. If desired, only one edge, only two edges, or only three edges of the display output surface may be curved using the fiber relay.
In yet another embodiment, shown inFIG. 11C, only the corners of the display panel are covered by fibers. The display may have a rectangular shape with an upper left corner, an upper right corner, a lower left corner, and a lower right corner. The corners may optionally be rounded corners. Afirst fiber relay142A is formed over a first corner (e.g., an upper-left corner) of the display panel, asecond fiber relay142B is formed over a second corner (e.g., an upper-right corner) of the display panel, athird fiber relay142C is formed over a third corner (e.g., a lower-left corner) of the display panel, and afourth fiber relay142D is formed over a fourth corner (e.g., a lower-right corner) of the display panel. Edge portions of the display panel that run between the corners, as well as a central portion of the display panel, are not covered by fibers. In this type of arrangement, a central portion of the display output surface (e.g., non-corner portions) may be planar (because light is being emitted from the central portion of the display without modification by the fibers). The corners of the display output surface, however, may use the fiber relays to have any desired three-dimensional shape (e.g., compound curvature). This example of the four corners of the display output surface being curved is merely illustrative. If desired, only one corner, only two corners, or only three corners of the display output surface may be curved using the fiber relay.
Forming fiber relays in the corners of the display may be particularly helpful given the limitations of bending the display panel itself. To help form a curved display output surface, the display panel may be bent. This may result in the display output surface being curved (even without the use of a fiber relay). However, the display panel may only be able to accommodate bends along a single axis at a time. Thus, forming a display output surface with certain three-dimensional shapes may still be difficult. Forming fiber relays in the corner of the display may enable the display output surface to have multiple bends (e.g., a rounded corner that is bent downwards). The display output surface may therefore use the four discrete fiber relays ofFIG. 11C to have compound curvature in the corners.
FIG. 12 is a top view of an illustrative display panel that is bent to form a curved display output surface.FIG. 12 depictsdisplay panel160 in an unbent state (e.g., before the extensions of the display panel have been bent). As shown, display panel160 (which may sometimes be referred to as a display active area that includes display pixels) may include display panel extensions (sometimes referred to as display panel tabs, bent regions, or bent portions of the display panel)160-1,160-2,160-3, and160-4. Each display panel extension is configured to be bent along a respective bend axis. Display panel extension160-1 is configured to be bent along bend axis182-1, display panel extension160-2 is configured to be bent along bend axis182-2, display panel extension160-3 is configured to be bent along bend axis182-3, and display panel extension160-4 is configured to be bent along bend axis182-4. Bend axes182-1 and182-4 may be parallel and bend axes182-2 and182-3 may be parallel. Bend axis182-1 may be perpendicular to bend axes182-2 and182-3. The display panel extensions may surround a central portion160-5 of the display panel that is not bent.
By bending the display panel as shown inFIG. 12, the periphery of the display output surface may be curved (as the display panel includes display pixels on the central portion and the display panel extensions). This example of the display panel having four display panel extensions (around the entire periphery of the display) that are bent is merely illustrative. If desired, the display panel may have only one display panel extension that is bent, only two display panel extensions that are bent, or only three display panel extensions that are bent. In all of these embodiments, any desired portion(s) of the display panel may be covered by fibers. The fibers may be used to further curve the display output surface (e.g., to have compound curvature), for example.
FIG. 13 is a cross-sectional side view of an illustrative electronic device with a bent display panel (e.g., the display panel ofFIG. 12) and a fiber relay. As shown, display panel extension160-3 is bent around bend axis182-3 relative to central display panel portion160-5. This helps promote a curved display output surface (e.g., display output surface184). The display inFIG. 13 also includesfiber relay142.Fiber relay142 includesfibers144 that guide light fromdisplay panel160 to displaycover layer162. The fibers may enable further curvature of the display output surface if desired. Bending the display panel as shown inFIG. 13 may minimize the relay distance required by fiber relay142 (which may improve the display performance).
The display panel may have additional extensions to accommodate desired curved display output surfaces while still only bending the display panel along a single bend axis at a time.FIG. 14 is a top view of an illustrative display panel that is bent to form a curved display output surface.FIG. 14 depictsdisplay panel160 in an unbent state (e.g., before the extensions of the display panel have been bent). As shown,display panel160 may have display panel extensions160-3 and160-4 bent along axes182-3 and182-4 respectively (similar to as discussed in connection withFIG. 12). It may be desirable to make additional bends to display panel extension160-3 (e.g., to further reduce the relay distance of a fiber relay that will overlap the corner of the display panel). However, as discussed previously each portion of the display panel can only be bent in one direction. Therefore, once display panel extension160-3 is bent along axis182-3, a planar portion of display panel extension160-3 may be bent along axis182-5.
When display panel extension160-3 inFIG. 14 is bent downwards (e.g., into the page),portion186 may be bent. The curvature of the bend may start at bend axis182-3 and be limited toregion186 of the display panel extension. The remainingportion188 of the display panel extension may be planar (even after the extension is bent along axis182-3). The remainingportion188 of the display panel extension may, for example, be positioned in the YZ-plane after the extension is bent inregion186. Thisplanar portion188 may have an extendedportion190 that is then bent along bend axis182-5. Theextended portion190 of the display panel may be used to form a rounded corner shape for the display.
FIG. 15 is a perspective view of the display panel ofFIG. 14 after the display panel has been bent. As shown inFIG. 15, the central portion160-5 of the display panel lies parallel to the XY-plane. The display panel extension160-4 is bent downwards (e.g., in the negative Z-direction) along bend axis182-4 (which is parallel to the X-axis). Display panel extension160-3 is bent downwards inregion186 along axis182-3 (which is parallel to the Y-axis). Finally,extension190 ofplanar portion188 is bent along axis182-5 into a rounded corner shape. The display panel may include display pixels on all of the display panel portions shown inFIG. 15. Therefore, even thoughextension190 is only bent once (thus satisfying the reliability requirements for the display panel), the display panel can approximate a display output surface with a rounded corner that is bent downwards (i.e., the display panel can approximate a display output surface with compound curvature).
Liquid crystal displays, organic light-emitting diode displays, and other types of displays that may be used to form the display panel may include a linear polarizer layer. For example, the liquid crystal display (LCD) inFIG. 3 includes anupper polarizer54 and the organic light-emitting diode (OLED) display inFIG. 4 includes a circular polarizer100 (that includes a linear polarizer). In these cases, the polarizer layer must be interposed between the display layer (e.g., the light-emitting diodes of an OLED display or the liquid crystal layer of an LCD display) and the outer surface of the electronic device. An arrangement of this type is shown inFIG. 16.
FIG. 16 is a cross-sectional side view of an electronic device with a display, a linear polarizer, and a fiber relay. As shown inFIG. 16,linear polarizer192 may be formed over display layers of the display (e.g., display panel160).Fibers142 are then formed over the linear polarizer and interposed between the linear polarizer and thedisplay cover layer162. In this arrangement, the display plane (e.g., display panel160) is spatially separated from the outer surface of the electronic device (e.g., the outer surface of display cover layer162), which can be aesthetically undesirable.
To minimize the distance between the display plane and the outer surface of the electronic device, polarizing fibers may be used infiber relay142. The linear polarizer can therefore be eliminated from the stack-up, moving the display plane closer to the outer surface of the electronic device (for improved aesthetics) and reducing the thickness of the display. An arrangement of this type is shown inFIG. 17. As shown,fiber relay142 includes polarizing fibers that will replace the function of thelinear polarizer192 fromFIG. 16.
Polarizingfibers142 inFIG. 17 may have a structure similar to those shown inFIG. 5 (e.g., with each fiber having a core surrounded by a cladding and a host matrix material between each fiber). The polarizing functionality may be achieved by adding a chiral dopant to the core of the fibers. In the polarized fibers, light of the desired polarization will be guided through the fiber. In contrast, light of the undesired polarization will be ejected out of the core and into the host matrix material. The host matrix material may be blackened to prevent light leakage if desired.
If the display ofFIG. 17 is a liquid crystal display,polarizing fibers142 may take the place of the upper polarizer of the liquid crystal display. For example,polarizing fibers142 may be attached totransparent substrate56 inFIG. 3 without an intervening linear polarizer layer. The polarizing fibers may be the only linear polarizer that is interposed between the liquid crystal layer of the liquid crystal display and the outer surface of the electronic device. If the display ofFIG. 17 is an organic light-emitting diode display,polarizing fibers142 may take the place of the linear polarizer in the circular polarizer of the liquid crystal display. For example,polarizing fibers142 may be attached to thin-film transistor circuitry92 inFIG. 4 without an intervening linear polarizer layer. The circular polarizer for the organic light-emitting diode display may still require a quarter wave plate. The polarizing fibers may be attached to a quarter wave plate for the circular polarizer without an intervening linear polarizer layer. The polarizing fibers may be the only linear polarizer that is interposed between the light-emitting diodes of the organic light-emitting diode display and the outer surface of the electronic device.
The polarizing fibers inpolarizing fiber relay142 may have any desired length (e.g., less than 10 millimeters, less than 1 millimeter, less than 100 microns, less than 10 microns, greater than 1 micron, greater than 10 microns, greater than 100 microns etc.). The polarizing fibers may cover any desired portion of the display panel (e.g., the entire display panel as shown inFIG. 11A, the edges of the display panel as shown inFIG. 11B, or the corners of the display panel as shown inFIG. 11C) and the display panel may have any desired number of bends.
FIG. 18 is a cross-sectional side view of an illustrative embodiment where the polarizing fibers form an outer surface of the electronic device. In this arrangement, no display cover layer may be formed over the polarizing fibers, allowing the display plane to appear to be on the outer surface of the electronic device. This type of arrangement allows for the possibility of opaque materials covering the display, as shown inFIG. 19.
FIG. 19 is a cross-sectional side view of an electronic device with adisplay cover layer162 that may be non-transparent (e.g., opaque). As shown inFIG. 19,display cover layer162 has a number ofopenings192 that receivefibers144 offiber relay142.Fibers144 may guide light directly from thedisplay panel160 to the outermost surface of the electronic device (e.g., surface184). Thefibers144 anddisplay cover layer162 may combine to form the outermost surface of the electronic device.Display cover layer162 may be formed from an opaque material in this embodiment. For example,display cover layer162 may be metal, ceramic, or another opaque material.
FIG. 19 shows one fiber formed in each opening ofdisplay cover layer162. This example is merely illustrative. If desired, more than one fiber may be formed in each opening ofdisplay cover layer162. The openings of the display cover layer may be formed and then the fibers may be inserted into the openings. Alternatively, the display cover layer may be grown or molded around the fibers such that the fibers are embedded in the display cover layer.
As shown inFIG. 19, afiller material164 may be formed in betweenfibers144 offiber relay142.Filler material164 may conform to the shape of the fibers to fill any voids between the fibers. This may help maintain the structural integrity of the fibers and keep the fibers in a desired position.Filler material164 may be any desired material.Filler material164 may be opaque or transparent. In some embodiments,display cover layer162 may be omitted andfiller material164 may be the only component maintaining the structure of the fibers. In this scenario,filler material164 may also form a portion of the outermost surface of the electronic device.
Fibers of the type shown inFIG. 19 may cover any desired portion of the display panel (e.g., the entire display panel as shown inFIG. 11A, the edges of the display panel as shown inFIG. 11B, or the corners of the display panel as shown inFIG. 11C) and the display panel may have any desired number of bends.
In various embodiments, an electronic device may include a display panel having first and second opposing edges that couple to third and fourth opposing edges to form four corners, a plurality of groups of fibers that are each aligned with a respective corner of the display panel, and a display cover layer formed over the plurality of groups of fibers. Each group of fibers may include a plurality of fibers that guide light from the display panel to a curved interior surface of the display cover layer.
Each fiber of the plurality of fibers of each group of fibers may include a cladding that surrounds a core with a higher index of refraction than the cladding. Each group of fibers may have a filler material that fills space between the plurality of fibers in that group of fibers. Each group of fibers may be attached between the display panel and a respective flexible substrate. Each flexible substrate may be attached to the curved interior surface of the display panel. Each fiber of the plurality of fibers of each group of fibers may include an activated photoactive material. Each fiber of the plurality of fibers of each group of fibers may be a polarizing fiber that serves as a linear polarizer. The display panel may have a planar central portion and a first display panel extension and the first display panel extension may run along the first edge of the display panel and may be bent around a first bend axis relative to the planar central portion of the display panel. The first display panel extension may have a curved portion and a planar portion and the planar portion may have an additional extension that is bent around a second bend axis.
In various embodiments, an electronic device may include display structures having an array of display pixels and a plurality of polarizing fibers formed on the display structures that guide light from the array of display pixels towards a display surface. The display structures may include liquid crystal display structures, the liquid crystal display structures may include a lower linear polarizer and a liquid crystal layer, and the plurality of polarizing fibers may serve as an upper linear polarizer for the liquid crystal display structures. The display structures may include organic light-emitting diode structures, the organic light-emitting diode structures may include a circular polarizer, and the plurality of polarizing fibers may serve as a linear polarizer for the circular polarizer. The electronic device may also include an opaque display cover layer with a plurality of openings and each polarizing fiber of the plurality of polarizing fibers may protrude into an opening of the plurality of openings.
In various embodiments, a method of forming a plurality of fibers between a display panel and a display cover layer in an electronic device includes forming a photoactive material between the display panel and the display cover layer and activating portions of the photoactive material to form the plurality of fibers with at least one light source. Each fiber of the plurality of fibers may guide light from at least one display pixel of the display panel to a curved interior surface of the display cover layer.
Activating the portions of the photoactive material to form the plurality of fibers with the at least one light source may include using a single laser to emit a beam of light through the photoactive material to form each fiber of the plurality of fibers. Activating the portions of the photoactive material to form the plurality of fibers with the at least one light source may include using first and second lasers to emit respective first and second beams of light through the photoactive material to form each fiber of the plurality of fibers. Only portions of the photoactive material that are exposed to both the first and second beams of light may be activated. The method may also include removing remaining portions of the photoactive material after activating the portions of the photoactive material to form the plurality of fibers. The method may also include adding a filler material between the plurality of fibers after removing the remaining portions of the photoactive material. Forming the photoactive material between the display panel and the display cover layer may include forming a photopolymer between the display panel and the display cover layer. Forming the photoactive material between the display panel and the display cover layer may include forming a chalcogenide glass between the display panel and the display cover layer.
The foregoing is merely illustrative and various modifications can be made by those skilled in the art without departing from the scope and spirit of the described embodiments. The foregoing embodiments may be implemented individually or in any combination.